Method of coloring hydrophobic fibers and films



United States Patent U.S. Cl. 8-4 4 Claims ABSTRACT OF THE DISCLOSURE A method of imparting color to shaped structures formed from polymers of propylene, which comprises applying to said structures an amine compound selected from the group consisting of aminodiphenyl amines and the salts thereof, said aminodiphenyl amine having the formula:

wherein the NH group is in the para or ortho position with respect to the group and X and Y each represent a member selected from the group consisting of hydrogen, halogen, alkyl, alkoxy, alkylamino, and amino, in a single bath containing an aqueous dispersion of said amino compound at a temperature of at least 50 C., adding to said bath an aqueous solution containing a hypochlorous acid compound selected from the group consisting of hypochlorous acid, alkali metal hypochlorites and alkaline earth metal hypochlorites, and thereafter heating said bath.

This invention relates to a method of imparting color to hydrophobic fibers and films and obtaining black Patented July 8, 1969 ice @ Q Y X wherein the N group is at the para or ortho position with respect to group and X and Y each represent hydrogen or halogen or an alkyl, alkoxy or alkylamino group; or a derivative thereof and thereafter treating in 'situ with a hypohalogen acid or a salt thereof the polypropylene fiber could be dyed to a deep black shade having colorfastness.

The amines of the foregoing Formula 1 which can be used in the present invention include, e.g., 4-amino-diphenylamine, 4-methoxy-4'-amino-diphenylamine, 4,4'-diamino-diphenylamine, 4-chloro-4'-amino-diphenylamine, 4-methyl-4'-aminodiphenylamine, 2-methoxy-4'-amino-diphenylamine, 4-methyl-2'-amino-diphenylamine, 4,2'diamino-diphenylamine, 2-methyl-4-amino-diphenylamine, 2methoxy-4-amino-diphenylamine and 2-ethylamino-4- amino-diphenylamine. These amines can be used either in the form of free amines or in the form of acid-added salts such as sulfates or hydrochlorides. Further, it is also possible to use a blend of two or more of these amines. While it is preferred normally to use these amines in an amount of 210% (OWF), a smaller or a greater amount may be used, depending upon the objective sought. In most cases however, the use of an amount greater than 20% (OWF) is not necessary. It was found that dyed products Whose rate of dye affinity was above 5% (OWF) was dyed to a shade deep enough to be satisfactory.

The oxidants used in the invention method include the hypochlorites such as sodium hypochlorite, potassium hypochlorite and calcium hypochlorite as well as hypochlorous acid and the bleaching powder solution. These oxidants can normally be used in an amout of at least 4 mols, and preferably 4-l6 mols, to each mol of the aminodiphenylamine or derivative thereof. It was found that the maximum rate of dye afiinity was obtained when the oxidant was used in an amount of 8 mols per mol of the amine.

In carrying out the invention method, the dyestuff must be well dispersed in the dye bath. For this purpose, effective are either the anionic or nonionic dispersants. The use of a dispersant having an amine radical hinders the color development. Further, for improving the color development, use can be made of the alcohols, such as aromatic alcohols, aliphatic alcohols, glycol, glycerine, polyethylene glycol, polyvinyl alcohol and water-soluble saccharoids, the phosphatic dissolving agents, such as sodium pyrophosphate and sodium tripolyphosphate, and the pussiates. The aminoalcohols and phenols become hindrances, however.

In practicing the invention method, the usually practiced dip dyeing and package dyeing methods can be employed. In this case, the material to be dyed and the dyestuff with the foregoing color development assistants are placed in the dye bath and then, while heating for awhile, agitation or circulation of the liquor is effected, after which an aqueous hypochlorite solution is added to effect the oxidation and color development. The oxidant is preferably added at above 50 C. After addition of the oxidant, the temperature is raised. By continuing the heating for to minutes while stirring or circulating the liquor, the color development is completed. The oxidation temperature should preferably be at least 80 C. From the standpoint of dye affinity and the color phase of the dyed product, the oxidant is preferably added at one time instead of in increments or gradually. The pH of the dye bath, on the other hand, is preferably neutral or alkaline from the point of the fastness of the dyed product to rubbing. The excellent colorfastness of the product to various agents which cause fading is ensured by washing the dyed product after dyeing, which washing also serves as the dechlorination operation. The preferred washing method is that consisting of treating the product for 20 to 30 minutes at above 80 C. with either a washing liquid containing l2 g./l. each of sodium hydrosulfite, a nonionic activator and sodium carbonate or a washing liquid containing about 5 g./l. of sodium thiosulfate and about 2 g./l. of soap; and thereafter washing with water.

Further, the present invention can not only be practiced by the foregoing dip dyeing and packaging methods but also by means of other methods such as, for example, the printing method.

In practicing the invention, no special skills or equipment are needed. According to the invention method, polypropylene fibers can be readily dyed at low cost to a deep black shade excelling in colorfastness to the various agents which cause fading by using the dyeing equipment that has been in common use heretofore. In the past, the polypropylene fibers could not be dyed to a deep black shade by the combination of an oxidant with the oxidation dyestuffs which were used for cotton and other textiles. Moreover, the fastness of the dyed products obtained in those instances were not satisfactory, and especially the fastness to rubbing and light was exceedingly unsatisfactory. Hence, it is truly surprising and unexpected to find that polypropylene fibers could be dyed to a deep black shade excelling in colorfastness by the method of the present invention which uses a combination of specific amines with specific oxidants. Further, it is to be noted that when the invention dyeing method is mployed in dyeing a mixed product of polypropylene fibers and rayon, the cellulose fiber is hardly dyed at all. On the other hand, it was found that by using sodium chlorate as the oxidant the rayon could be dyed to a deep black shade.

The dyeing method of this invention can not only be practiced with the polypropylene fiber but also with polypropylene film as well as in dyeing fibers and films made from the hydrophobic polymers such as fibers and films of the polyolefinic resins besides polypropylenes, such as polyethylene, the polyester resins such as polyethylene terephthalate, the polyvinyl chloride and polyvinylidene chloride resins, the polyurea resins, the polyamide resins such as polycaprol'actam, the polyacrylonitrile resins, polyvinyl alcohol resins and polyurethane resins.

EXAMPLE 1 Combinations of the following commercially available aromatic amines and oxidants are used and samples of wooly knit material of polypropylene are dyed.

Aromatic amines used (1) o-phenylenediamine (2) p-phenylenediamine (3) o-aminophenol hydrochloride (4) m-aminophenol (5) 4-methoxy-4-amino-diphenylamine (6) 2,4-diaminophenol dihydrochloride (7) 3,4-diaminotoluene (8) p-phenylenediamine sulfate (9) benzidine (10) aniline (11) 2,4-diaminophenol (12) 2,4-diaminotoluene 13 4-amino-diphenylamine (l4) 4,4-diamino-diphenylmethane (l5) 4,4-diamino-diphenylsulfone (l6) 4,4-diaminodiphenyl ether (17) o-toluidine (l8) m-toluidine (l9) p-toluidine (20) p-octylamine The dye liquor is prepared by adding and dispersing in cc. of water a solution of 0.2 g. of the amine in 10 cc. of ethanol. Into this dye liquor are placed 2 g. of the wooly knit material of polypropylene, after which the dye liquor is heated to boil the knit material for 60 minutes, and then after adding cc. of one of the following oxidant solutions, the heating is continued for another 60 minutes.

Oxidant solutions used A. Sodium hypochlorite.l5 cc. of an aqueous solution of sodium hypochlorite (available chorine 4.0%) diluted with 200 cc. of water.

B. Sodium chlorite.A ZOO-cc. aqueous solution in which is dissolved 2 g. of sodium chlorite, 1.5 g. of ammonium vanadate, 1 cc. of 35% hydrochloric acid and 20 g. of sodium chloride.

C. Sodium chlorate.-A ZOO-cc. aqueous solution in which is dissolved 2 g. of sodium chlorate, 1.5 g. of ammonium vanadate, 1 cc. of 35% hydrochloric acid and 20 g. of sodium chloride.

After completion of the dyeing, the samples were soaped for 30 minutes in 100 cc. of an aqueous solution containing 2 g./l. of sodium carbonate and 2 g./l. of a nonionic activator, at 85 C., then washed with water and dried.

The results obtained are shown in Table I. In Table I the term undyed with respect to dye affinity means that the sample was either discolored or was not dyed at all; good with respect to lightfastness indicates that lightfastness of at least Class 3 was obtained by the AATCC method, whereas bad means that the lightfastness was less than Class 3; and colorfastness to rubbing is shown by the AATCC classification. The asterisk indicates that there was a tarlike substance adhering to the dyed samples.

at the boil followed by washing with hot water to obtain a dyed material. The dyed material is then treated for 30 minutes by boiling in a solution comprising 2 g./l. each of sodium hydrosulfite and sodium carbonate. The dyed material is thereafter soaped in a bath containing 2 g./l. of a nonionic activator Pellipon 8-2 (a product of Yoshimura Yuka Co., Ltd.) and washed with water. The dyed product so obtained is of pure black shade excelling in color fastness to the various agents which cause fading.

EXAMPLE 5 50 g. of 4-amino-diphenylamine (purity 70.8%) are kneaded with 50 g. of carboxymethyl cellulose and 50 g. of Labellin while adding water to prepare a pastelike dye slurry. Employing a jet-type hank dyeing machine, one kg. of polypropylene (65%)-rayon (35%) blended yarn is introduced, after which 30 l. of water is added and the temperature raised. At 40-50 C., the foregoing dye slurry is added, following which the temperature is raised still further and the treatment is carried out for one hour at 100 C. Thereafter, the temperature is lowered to 70 C., one liter of sodium hypochlorite (available chlorine 10.3%) is added and by raising the temperature the oxidation treatment is carried out for 30 minutes at 100 C. Then, by washing with hot water, reducing and soa ing a product is obtained wherein the polypropylene is dyed black whereas the rayon remains undyed.

EXAMPLE 6 A solution of 0.2 g. of 4-methoxy-4-amino-diphenylamine in 5 cc. of ethyl alcohol is added to water containing 2 g./l. of a dispersant (sodium alkylbenzene sulfonate) and dispersing therein. Two g. of polypropylene staples are dipped in this dispersion whose temperature is then raised. After treating for minutes at 50 C., 8 cc. of sodium hypochlorite solution are added to the dispersion, whose temperature is then raised to carry out the dyeing operation for minutes at the boil. After treating the dyed material for 30 minutes by boiling in a solution comprising 5 g./l. of sodium sulfate and 2 g./l. of soap, it is washed in a bath containing 2 g./l. of nonionic activator followed by washing with water.

The dyed product exhibited a black shade which had excellent colorfastness to the various agents which cause fading.

formula:

I NHz wherein the NH group is in the para or ortho position with respect to the group, and X and Y each represent a member selected from the group consisting of hydrogen, halogen, alkyl, alkoxy, alkylamino and amino, in a single bath containing an aqueous dispersion of said amino compound at a temperature of at least C., adding to said bath an aqueous solution containing a hypochlorous acid compound selected from the group consisting of hypochlorous acid, alkali metal hypo chlorites, and thereafter heating said bath.

2. The method according to claim 1, wherein said aqueous solution contains the hypochlorous acid compound in an amount corresponding to 4 to 16 moles of available chlorine per mol of said aminodiphenyl amine compound.

3. The method according to claim 1, in which said final heating is to a temperature of at least 80 C.

4. The method according to claim 1, in which 4-arninodiphenyl amine is used in the aqueous dispersion.

References Cited UNITED STATES PATENTS 3,036,875 5/1962 Schlack et al. 8-32 NORMAN G. TORCHIN, Primary Examiner.

T. J. HERBERT, JR., Assistant Examiner.

US. Cl. X.R. 8-32,

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,454,348 July 8, 1969 Harutoshi Kurokawa et al.

It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Column 8, lines 7 to 9, the formula should appear as shown below:

NH NHZ Signed and sealed this 21st day of April 1970.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. WILLIAM E. SCHUYLER, JR. Attesting Officer Commissioner of Patents 

